Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753815AbYBLXcY (ORCPT ); Tue, 12 Feb 2008 18:32:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752198AbYBLXcO (ORCPT ); Tue, 12 Feb 2008 18:32:14 -0500 Received: from stargate.chelsio.com ([12.22.49.110]:4765 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751954AbYBLXcN convert rfc822-to-8bit (ORCPT ); Tue, 12 Feb 2008 18:32:13 -0500 X-Greylist: delayed 1014 seconds by postgrey-1.27 at vger.kernel.org; Tue, 12 Feb 2008 18:32:12 EST Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [ofa-general] Re: Demand paging for memory regions X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Tue, 12 Feb 2008 15:14:23 -0800 Message-ID: <8A71B368A89016469F72CD08050AD334026D5C23@maui.asicdesigners.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [ofa-general] Re: Demand paging for memory regions Thread-Index: AchtyFtJfix6DzKHTGuMwZ9fQmN2HwABDtTQ References: <20080208234302.GH26564@sgi.com><20080208155641.2258ad2c.akpm@linux-foundation.org><20080209012446.GB7051@v2.random><20080209015659.GC7051@v2.random><20080209075556.63062452@bree.surriel.com><47B2174E.5000708@opengridcomputing.com> From: "Felix Marti" To: "Roland Dreier" , "Christoph Lameter" Cc: "Rik van Riel" , , "Andrea Arcangeli" , , , , , , , "Robin Holt" , , "Andrew Morton" , Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2082 Lines: 51 > -----Original Message----- > From: general-bounces@lists.openfabrics.org [mailto:general- > bounces@lists.openfabrics.org] On Behalf Of Roland Dreier > Sent: Tuesday, February 12, 2008 2:42 PM > To: Christoph Lameter > Cc: Rik van Riel; steiner@sgi.com; Andrea Arcangeli; > a.p.zijlstra@chello.nl; izike@qumranet.com; linux- > kernel@vger.kernel.org; avi@qumranet.com; linux-mm@kvack.org; > daniel.blueman@quadrics.com; Robin Holt; general@lists.openfabrics.org; > Andrew Morton; kvm-devel@lists.sourceforge.net > Subject: Re: [ofa-general] Re: Demand paging for memory regions > > > > Chelsio's T3 HW doesn't support this. > > > Not so far I guess but it could be equipped with these features > right? > > I don't know anything about the T3 internals, but it's not clear that > you could do this without a new chip design in general. Lot's of RDMA > devices were designed expecting that when a packet arrives, the HW can > look up the bus address for a given memory region/offset and place the > packet immediately. It seems like a major change to be able to > generate a "page fault" interrupt when a page isn't present, or even > just wait to scatter some data until the host finishes updating page > tables when the HW needs the translation. That is correct, not a change we can make for T3. We could, in theory, deal with changing mappings though. The change would need to be synchronized though: the VM would need to tell us which mapping were about to change and the driver would then need to disable DMA to/from it, do the change and resume DMA. > > - R. > > _______________________________________________ > general mailing list > general@lists.openfabrics.org > http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib- > general -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/